Classifications

• • G—PHYSICS
  • G08—SIGNALLING
  • G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
  • G08B13/00—Burglar, theft or intruder alarms
  • G08B13/22—Electrical actuation
  • G08B13/24—Electrical actuation by interference with electromagnetic field distribution
  • G08B13/2402—Electronic Article Surveillance [EAS], i.e. systems using tags for detecting removal of a tagged item from a secure area, e.g. tags for detecting shoplifting
  • G08B13/2405—Electronic Article Surveillance [EAS], i.e. systems using tags for detecting removal of a tagged item from a secure area, e.g. tags for detecting shoplifting characterised by the tag technology used
  • G08B13/2408—Electronic Article Surveillance [EAS], i.e. systems using tags for detecting removal of a tagged item from a secure area, e.g. tags for detecting shoplifting characterised by the tag technology used using ferromagnetic tags
  • G08B13/2411—Tag deactivation
• • G—PHYSICS
  • G06—COMPUTING; CALCULATING OR COUNTING
  • G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
  • G06K7/00—Methods or arrangements for sensing record carriers, e.g. for reading patterns
  • G06K7/10—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation
  • G06K7/10544—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation by scanning of the records by radiation in the optical part of the electromagnetic spectrum
  • G06K7/10821—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation by scanning of the records by radiation in the optical part of the electromagnetic spectrum further details of bar or optical code scanning devices
  • G06K7/10881—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation by scanning of the records by radiation in the optical part of the electromagnetic spectrum further details of bar or optical code scanning devices constructional details of hand-held scanners
• • G—PHYSICS
  • G08—SIGNALLING
  • G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
  • G08B13/00—Burglar, theft or intruder alarms
  • G08B13/22—Electrical actuation
  • G08B13/24—Electrical actuation by interference with electromagnetic field distribution
  • G08B13/2402—Electronic Article Surveillance [EAS], i.e. systems using tags for detecting removal of a tagged item from a secure area, e.g. tags for detecting shoplifting
  • G08B13/2428—Tag details
  • G08B13/2437—Tag layered structure, processes for making layered tags
  • G08B13/2442—Tag materials and material properties thereof, e.g. magnetic material details
• • G—PHYSICS
  • G08—SIGNALLING
  • G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
  • G08B13/00—Burglar, theft or intruder alarms
  • G08B13/22—Electrical actuation
  • G08B13/24—Electrical actuation by interference with electromagnetic field distribution
  • G08B13/2402—Electronic Article Surveillance [EAS], i.e. systems using tags for detecting removal of a tagged item from a secure area, e.g. tags for detecting shoplifting
  • G08B13/2428—Tag details
  • G08B13/2437—Tag layered structure, processes for making layered tags
  • G08B13/2445—Tag integrated into item to be protected, e.g. source tagging
• • G—PHYSICS
  • G08—SIGNALLING
  • G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
  • G08B13/00—Burglar, theft or intruder alarms
  • G08B13/22—Electrical actuation
  • G08B13/24—Electrical actuation by interference with electromagnetic field distribution
  • G08B13/2402—Electronic Article Surveillance [EAS], i.e. systems using tags for detecting removal of a tagged item from a secure area, e.g. tags for detecting shoplifting
  • G08B13/2465—Aspects related to the EAS system, e.g. system components other than tags
  • G08B13/2468—Antenna in system and the related signal processing
  • G08B13/2474—Antenna or antenna activator geometry, arrangement or layout

Definitions

• the subject invention concerns an device in an alarm system and is designed to sense the entrance of an article equipped with a par ⁇ ticular marker into a magnetic field generated for the purpose of this sensing operation.
• the marker comprises at least one strip of a material having ferromagnetic soft properties and sensing means are provided to sense the characteristic tones generated by the ferromagnetic soft strip material in the magnetic field. Adjacent each strip of ferromagnetic soft material there is arranged a second strip of a material having pro- perties allowing it to be magnetized but which material is non-magnetic in its untreated state.
• a means is designed to neutralize the marker, ensuring that the alarm remains inactivated when the marker passes through the magnetic field.
• the device is intended for use 1n alarm systems in in retail stores, libraries and similar premises to prevent shoplifting and thefts.
• shoplifting and thefts from shops and stores are quite common.
• the waste in shops and stores in Sweden is estimated to quite considerable amounts per household and year.
• the shoplifting may be of an unplanned and impulsive type but also be well-planned and carried out on a large scale.
• Alarm devices of the type defined in the introduction are well known and used in various applications. These alarm devices are designed to make use of the fact that when a piece of metal (preferably of a so-called high-permeability material) enters a sinusoidally varied magnetic field a voltage is induced in coils arranged in the vicinity of the applied magnetic field. Each metal which enters the magnetic field generates a voltage which is characteristic of that metal. This voltage consists of a basic component and a number of characteristic harmonics. In alarm devices of the kind described above the harmonics generated by a particular material included in the marker of an article alerts the alarm. An alarm device functioning in accordance with this principle is described in FR 763 681.
• US 1 538 385 is described an example of an alarm device functioning on a somewhat different principle from the one described above.
• Two magnetic fields are established at the exit from a shop or similar premises. These two magnetic fields oscillate at different fre ⁇ quencies and when a marker including ferromagnetic soft material is ⁇ introduced into these magnetic fields it will give off a tone of a frequency representing the difference between the frequencies with which the two magnetic fields oscillate.
• Sensing means are set to detect the tones of this frequency and upon detection thereof trigger off the alarm.
• the purpose of the subject invention is to provide an alarm device in which in a simple and efficient manner the characteristics of the marker may be altered in such a manner that it may be neutralized and be passed through the magnetic field without triggering off the alarm.
• the second strip is a continuous strip which is sufficiently thin to allow lasting magnetic poles which are limited as to their extension in the lengthwise direction of the second strip, to generate irrespective of the cross-sectional profile configuration of the second strip, that said neutralization means is arranged, upon said neutralization, to magnetize the second strip in such a manner that the latter will comprise a number of magnetic poles of limited extension, whereby the ferromagnetic soft strip becomes magnetically saturated.
• Fig. 1 is a perspective view of an article which is provided with a marker for activation of the alarm, in the form of a label
• Fig. 2 is a detail view from the side of a means designed to neutralize the marker
• Fig. 3 is an explosive view of the parts forming a label in accordance with the invention.
• Fig. 4 illustrates schematically the magnetic charge distri- bution over the strips incorporated in the label after the neutraliza ⁇ tion of the latter.
• An article 10 is provided with a label 12.
• the latter may, as shown, be provided with an EAN Code i.e. European Article Numbering -- Code (so-called rib code). Codes of this kind are well known and in general use.
• the code is read by means of a read pen 14 which is passed across the code in the lengthwise direction thereof across the ribs.
• the label 12 On its lower face the label 12 is provided with two strips (ribbons of foil), a narrower strip 16 and a wider strip 18.
• the narrower one of the strips is of a ferromagnetic soft material which possesses the properties of having a high permeability, being non-magne- tic in itself and being incapable of being magnetized but conducts mag ⁇ netism well.
• the broader strip 18 is of a ferromagnetic hard material (such as iron) having the property of being non-magnetic when untreated but being magnetizable.
• the alarm device in accordance with the invention comprises a magnetizing means 20 which is designed for being mounted on the read pen 14.
• a magnetizing means 20 which is designed for being mounted on the read pen 14.
• it is provided with a centre part 22 having an aperture formed therein.
• From the centre part project two arms 24, each one carrying at its outer end a small magnet 26 (see Fig. 2).
• Both mag ⁇ nets 26 have the north pole facing downwards.
• One of the arms is slight- ly longer than the other one to compensate for the normally tilted posi ⁇ tion of the pen.
• the alarm device also has a magnetic field which is estab ⁇ lished in a conventional and prior-art manner in a sensing zone close to the store exit. This is not illustrated in the drawings but its function. in the inventive object is in principle identical to that of prior-art technology devices.
• the alarm device in accordance with the invention operates in the following manner.
• harmonics are genera- ted. These harmonics are detected in accordance with the invention by sensing means which may include aerials. As a result, if an article 10 carrying a non-treated label enters the magnetic field, this is detected and the alarm is triggered off.
• the read pen 14 When the article 10 is purchased the read pen 14 is passed over the EAN Code to read the price code of the article.
• the magnetizing means 20 On the read pen 14 the magnets 26 thereof then are passed across the two strips 16, 18 which are arranged essentially in the transverse direction across the EAN Code (cf. Fig. 1). From a ma ⁇ nufacturing point of view it is most simple to position the strips 16, 18 slightly diagonally across the label 12.
• the strip 18 will be magne- tically charged in the manner appearing from Fig. 4. Two north poles and three south poles are clearly distinguishable in the strip 18.
• the effect of the magnetizing condition is magnetic saturation of the ferro magnetic soft material and consequently the latter can no longer genera ⁇ te harmonics in a magnetic field. As a result, no alarm will be trig- gered off when the article enters the magnetic detection field.
• the magnetized strip 18 could be said to "blot out" the strip 16 by inter ⁇ ference.
• this strip preferably is continuous and has a uniform profile configuration.
• the strip may be manufactured in a more simple and efficient manner than is the case with corresponding prior-art elements of ferromagnetic hard materials.
• the proportions between the ferromagnetic soft and the ferromagnetic hard materials should be such as to ensure that at least 60% of the total mass is constituted by ferromagnetic hard material.
• the ferromagnetic hard strip 18 is thin with the result that it may exhibit evident localized poles (see Fig. 4). It is also pos ⁇ si le and advantageous to form more poles than the number shown in Fig. 4.
• a further advantage inherent in the alarm device in accordance with the invention is that several smaller and less strong magnets 26 are used instead of one comparati ely strong magnet, as is the case in prior-art technology devices.
• the magnet often is mounted at the cash-register desk in the shop. The article is passed across this magnet to neutral ize the marker. Articles such as videotapes and the l ike may be damaged by a strong mag- net. Account cards or equi valent items, if carelessly thrown onto the cash-register desk, could by mi stake end up on the magnet and be ruined.
• the small er and less strong magnets used in the device in accordance with the invention generate weaker magnetic fields wi th consequential reduction of this type of ri sk.
• the device in accordance with the invention could be adapted to i ts intended usage and poi nt of appl icati on.
• a comparatively long strip 16 may requi re a larger number of pol es in the strip 18 than the number shown.

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• Physics & Mathematics (AREA)
• Engineering & Computer Science (AREA)
• Electromagnetism (AREA)
• General Physics & Mathematics (AREA)
• Automation & Control Theory (AREA)
• Computer Security & Cryptography (AREA)
• Health & Medical Sciences (AREA)
• General Health & Medical Sciences (AREA)
• Toxicology (AREA)
• Artificial Intelligence (AREA)
• Computer Vision & Pattern Recognition (AREA)
• Theoretical Computer Science (AREA)
• Signal Processing (AREA)
• Burglar Alarm Systems (AREA)
• Alarm Systems (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=20353278

Family Applications (1)

Country Status (8)

Families Citing this family (41)

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• 1983
  • 1983-11-11 SE SE8306208A patent/SE440002C/sv not_active IP Right Cessation
• 1984
  • 1984-11-09 WO PCT/SE1984/000381 patent/WO1985002285A1/en not_active Application Discontinuation
  • 1984-11-09 AU AU36119/84A patent/AU572232B2/en not_active Ceased
  • 1984-11-09 BR BR8407357A patent/BR8407357A/pt unknown
  • 1984-11-09 US US06/758,669 patent/US4652863A/en not_active Expired - Fee Related
  • 1984-11-09 EP EP84904211A patent/EP0162886A1/en not_active Ceased
• 1985
  • 1985-07-09 DK DK313085A patent/DK313085A/da unknown
• 1986
  • 1986-04-30 FI FI861824A patent/FI861824A0/fi not_active Application Discontinuation

Non-Patent Citations (1)

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